Using Exchange 2010, I am trying to enable some anti-spam measures using the Message-ID domain classification:
So far I have had not a lot of success.
Created new transport rule on Hub Transport Server that:
On condition: "when the message header matches text patterns"
"Message-ID" matches 'contoso.com$' or 'fabrikam.com$' or 'fourthcoffee.com$'
forward the message to 'email@example.com' for moderation
The $ sign is the regular expression to match the end of the Message ID as shown as http://technet.microsoft.com/en-us/library/aa997187.aspx
The domains are examples and not actually used in my test!